ML19347C277
| ML19347C277 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 09/30/1980 |
| From: | Fiorelli G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Gerstner W ILLINOIS POWER CO. |
| References | |
| NUDOCS 8010170185 | |
| Download: ML19347C277 (1) | |
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NUCLCAR REGULATORY COMMISSION 5
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GLEN ELLYN,ILLINot5 60137 i
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Docket No. 50-461 Illinois Power Company i
ATTN: Mr. W. C. Gerstner j
Executive Vice President 500 South 27th Street Decatur, IK 62525 Gentlemen:
i Thank you for your interim report dated September 22, 1980, pursuant to 10 CFR 50.55(e) regarding attachment welds of swing barriers j
dividing the cabinets into bays had failed during shipment. We will review your final report on this matter upon receipt.
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Your cooperation with us is appreciated.
l Sincerely, 4
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' cz./ M G.
orelli, Chief Reactor Construction and
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Engineering support Branch i
cc: Director, RCI/IE Director, AEOD Chief, OEB/MPA IE Files t
cc w/ltr dtd 9/22/80:
4 Central Files PDR Local PDR NSIC TIC P
Mr. Dean Hansell, Office of Assistant Attorney General Mr. Gary N. Wright, Chief Division of Nuclear Safety s
i 8010170/F5 S
U-0186 Ll4-80(09-22)-9 ILLIN0/S POWER 00MPANY
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500 SOUTH 27TH STREET, OECATUR, ILUNOIS 62525 September 22, 1980 Mr. James G. Keppler Director, Region III Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
Clinton Power Station Unit 1 Docket No. 50-461 Construction Permit No. CPPR-137 Our letter of February 26, 1980 notified you of a reportable deficiency under the requirements of 10CFR50.55(e) and stated that a complete report would be submitted in approximately ninety days.
Originally it was estimated that the repairs would be completed in that time frame.
It now appears that the actual repairs will not be completed until late 1981; therefore, an update of the findings is being presented at this time.
1.
Statement of Reportable Deficiency On-site receipt inspection of the control room termina-tion cabinets revealed that some of the attachment welds of the swing barriers dividing the cabinets into bays had failed during shipment.
2.
Investigation During the receipt inspection of the Power Generation Control Complex (PGCC) termination cabinets, it was dis-covered that one of the swing barriers in each of three (3) of the twenty-one (21) cabinets had separated from the hinge attaching it to the cabinet frame.
The design drawing for the barrier specifies plug or spot welds on four-inch (4") centers for the full length of the hinge attachment.
The manufacturer (Hogan Manufacturing Company) had selected the plug weld alternative which, in these three cases, did not holdup under the rigors of shipment.
Further investigation revealed that the welds had failed due to lack of fusion and that some plug welds on other barriers were also unacceptable for the same reason.
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James G. Keppler September 22, 1980 3.
Corrective Action Nonconformance Report (NCR) No. 2968 was written documenting this problem and submitted to General Electric Company (GE) for dispositioning.
GE's disposition will require removal of the barriers from all cabinets for off-site repairs.
The barriers will be removed from the cabinets and shipped to the repair facility sometime prior to the end of 1980.
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Since installation of field cables is facilitated by the absence of these barriers, present plans are to leave them out until most of this work is done.
Accordingly, re-installation is not anticipated until late in 1981.
Since j
the specific corrective action involves reworking all of the barriers to meet the original design requirements, and this equipment represents all of the termination cabinets for the Project, no generic corrective action to avoid recurrence has been undertaken.
4.
Safety Implications / Significance It is believed that these barriers failed during transit j
to the Clinton Power Station.
The actual loading condi-tions imposed on the barriers is not known and it would be impracticable to attempt to quantify the loads which were imposed.
It can be assumed, however, that if the condition had gone undetected, it is possible that one or more bar-1 riers could have separated from the hinge attachment during a severe seismic event.
If a barrier came completely loose i
from its mooring, it would most probably fall to the side, i
possibly coming to rest against terminal blocks at its upper end.
Although barrier-type terminal blocks are em-played in the design, it is possible that the impact of the falling panel on the terminal blocks could sufficiently damage the barriers between terminals to short circuit some of the wiring, which could include critical circuitry in one safety division.
If more than one failure occurred and the failure followed the same course and caused the same damage to the circuitry in another safety division, the ability of the plant to shut down or to be maintained in a safe shut-down condition could have been compromised.
Since the actual repairs have not been made at this time, we i
submit this as an interim report in accordance with 10CFR50.55(e) i i
1
Jcmes G.'Keppler September 22, 1980 A
and trust that it is sufficient for your analysis and evaluation of the deficiency and the corrective action.
The cabinets are i
available for your inspection at any time, and the reworked barriers will be available for your inspection when they are returned from the off-site repair facility.
Sincerely, L. J. Koch Vice President i
l cc:
H H. Livermore l
NRC Resident Inspector l
l Director, Office of I&E, NRC, l
Washington, D.C.
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